<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<style>
    .container{
        position: fixed;
        top: 0;
        left: 0;
        right: 0;
        bottom: 0;
        text-align: center;
        font-size: 0;
        white-space: nowrap;
        overflow: hidden;
    }
    .container::after{
        content: '';
        vertical-align: middle;
        height: 100%;
    }
    .dialog{
        display: inline-block;
        vertical-align: middle;
        text-align: left;
        font-size: 14px;
        white-space: nowrap;
        background-color: red;
    }
</style>
<body>
    <div class="container">
        <div class="dialog">我永远喜欢20姬！</div>
    </div>
</body>
</html>